1. Technical Field
The present disclosure relates to a light source, a light-emitting module having the light source and a backlight unit (BLU) having the light source, and more particularly, to a light source including a light-emitting diode (LED) mounted on a substrate, a light-emitting module having the light source and a BLU having the light source.
2. Discussion of the Related Art
A liquid crystal display (LCD) apparatus includes a light source unit.
The light source unit may include a cold cathode fluorescent lamp (CCFL) or the LED as a light source. The LED includes a semiconductor layer emitting light based on an electric current. About 20% to about 30% of electrical energy applied to the LED is converted into light energy and the rest of the electrical energy applied to the LED is converted into thermal energy. Heat generated in the thermal energy conversion process may decrease the light-emitting efficiency of the LED.
When LEDs are used in a direct illumination type BLU in which a plurality of the light sources are disposed directly under the display panel, the LEDs are mounted on a printed circuit board (PCB) on which a power line pattern is formed. A power-transmitting substrate transmits driving power to the LED through the PCB.
The LED has low heat resistance. Thus, the heat generated from the LEDs needs to be dissipated to the outside of the LED.
The light-emitting efficiency of each of the LEDs varies according to a heat-dissipating structure of the light source unit. When a 40-inch BLU includes about a hundred LEDs of a top view type, the heat generated from the LEDs may have a harmful effect on the operational efficiency of the BLU and the display quality of a display panel.